Heat exchange device



April 8, 1952 H. T. BOOTH HEAT EXCHANGE DEVICE Filed April 21, 1949 'uvmvrox Ha rrr 7500M H/S A770 heat exchange Patented Apr. 8, 1952 V Harry '1. Booth, Dayton,

Aircraft Products, Inc., Dayton,

ration of Ohio Ohio, assignor to United Ohio, a corpo- Application April 21, 1949, SerialNo. 88,728 12 Claims; (Cl. 257-128) This invention relates to heat exchange devices of the kind characterized by a supporting shell and a core unit within the shell made :up primarily of an assembly or bundle of closely spaced apart thin walled tubes arranged :for the flow of a first fluid around and between ,the tubes, and for the flow of a second fluid through thetllbes. Among other things, such a device is useful as an aircraft oil cooler, with the oil constituting the aforesaid first fluid and passing :to'and from the core through radial openings in, the shell, the cooler being arranged for the flow through the tubes of the aforesaid second 'fiuidwhich, ordinarily, is air.

The instant invention has particular, although not limited, application to aircraft oil coolers. Among the improvement objectives in such devices have been a reductionin size and weight, without sacrifice of heat exchange area, andja construction simplifying both initial assembly and repair procedures. Weight reduction :ispossible through use of the so-calledlightgmetals, such as, aluminum, and a successiulreduction in size has been accomplished by. eliminating the conventional warm-up byepass chamber .sur-

rounding the shell and substituting therefor a more direct lay-pass and, vertical fl-ow :tubes cc tending transversely through the assembly. 0f

tubes. Inasmuch as the connections between the tubes and between the tubes andgthe shell have, in the past, been made by soldering, brazing and like techniques, efforts to use the light metals in oil coolerstructures have had inconsistent, results, and, even. where. partly successful, have materially added to the-difficultiesnand cost of manufacture and of repair.

More recently, there-has been proposed a construction utilizing header plates to mount the heat exchange tubes and all mechanical connection'sin the form of simple ring seals between the tubes and between the tubes and shell. Any

metal may be used for the construction material,

andthe absence of any need of metal working .meansthat repair work, iorexample the removal and replacement of a damaged tube, is reduced to the simplest of terms.

The present invention isspecifically concerned i with a modification of or improvement in the mechanically constructed oil cooler above described, although, as will be evident from the following'disclosure, it is applicable to a variety ofqheat exchange devices, including oil coolers with or without the external warm-up chamber and whatever material andcsealing devices are used intheir construction.

One object of the invention isto simplify the task of assembly of the oil cooler by enabling the complete core unit to be more readily built up as a unit and mounted as a whole within the supporting shell. A particular feature of the invention in this connection is the provision made for installation of the transverse flow tubes in the core when the cooler is of the type having no external warm-up chamber. There is built into the core, according to this feature of the invention, a tubular chamber directly communieating with the shell inlet andreceivingthe one ends of the transverse flow tubes.

With regard to the internal tubular chamber, it is another object of the invention to. provide such a chamber for the use described, andfor such other uses as may be desired.

A further object of the invention is -to provide for access to the tubular chamber-through the shell :for the introduction of fastening devices tosecure the core unit relatively to the shell, this feature of the invention having special application to the described mechanically connected cooler wherein no provision is made nor ordinarily required for uniting the core unit to the shell.

Still another object of the. invention is further to simplify fabrication and assembly of the cooler, and to provide a strong and inexpensive shell, by constructing the shell of cast metal with the inlet, outlet and by-pass openings formed integrally therein. Heretofore the shell has been made of rolled sheet metal with the fluid openings embodied in a machined fitting welded or otherwise secured to the sheet metal.

Other objects and structural detain oftheinvention will appear from the following description when read in connectionwith the accompanying drawing," wherein: j

Fig. l, is a view substantially in longitudinal section of an oil cooler constructed in accordance valve for the oil an aluminum ,alloy or other light metal. ,Qn its external surface, at a side thereof, which will hereinafter be referred to as the top of the heat exchange device, there is formed a flange I I having three longitudinally spaced openings I2, I3, and I4. Within the flange II, the opening I2 communicates with a chamber I 5 and registers with an opening I6 connecting the chamber I5 to the interior of the shell III. A similar chamber I1 and opening I8 are associated with opening I3. Opening I4 communicates with a chamber I9 in the flange II. which chamber is transversely elongated with respect to the chambers I5 and I I, and is, in turn, connected to the interior of the shell through an arcuate opening 2I, the ends of which extend beyond and are in effect circumferentially oiT-set with respect to the openings I6 and I8.

Supported within the shell I 0 adjacent the opposite ends thereof are respective header plates 22. The header plates 22 present a large number of closely spaced openings 23 which mount and support the ends of heat exchange tubes 24, arranged for the passage of a fluid, such as air, therethrough to cool or to heat the tubes according to the function of the device. The ends of the tubes24 extend through and beyond the openings 23 and are expanded so that the header plates are prevented from outward motion relatively to each other. The medial portions of the tubes are spaced apart for the flow of another fluid, such as oil, around and between the tubes. The internal faces of the header plates 22 are formed with transverse spaced grooves to receive baffle plates 25. 'The baffles 25 are constructed with openings 30 adjacent their one ends and adjacent bafiies occupy an inverse position with respect to one another in such wise as to define a tortuous fluid flow passage within the space enclosed by the shell II].

The lowermost baffle 25 is spaced a short distance from the bottom of the shell I 0 and defines therewith a header chamber 26 which may represent the start or the terminus of the tortuous fluid flow passage, depending upon whether the heat exchange device is arranged for conventional or so-called reverse flow operation.

The internal wall of each header plate is further formed with a shallow recess 21 which is contiguous with the periphery of the header plate. The recesses 21 in the respective header plates lie opposite one another and receive the ends of a cylindrical open-ended manifold 28. The manifold 28, accordingly, is supported by and between the header plates 22 and has a surface registering with the periphery of the header plates which are so arranged in the assembly of the device as to place the manifold 28 beneath the flange II and diametrically opposite the header chamber 26. Extending between and interconnecting the manifold 28 and the header chamber 26 is a series of flow tubes 29 which are spaced apart for a free flow of oil between the tubes exteriorly thereof. The upper ends of the tubes 29 extend into the manifold 28 and may be held against axial motion relatively to the manifold by a variety of means, for example, by a press fit, by brazing, or by swaging. The flow tubes extend transversely through the assembly of heat exchange tubes 24 and through suitable openings provided in the bafile plates 25, and their lower ends extend into and communicate with the header chamber 26.

The manifold 28 has a pair of longitudinally spaced openings to register with the openings I6 and I8 in the shell I0, and mounts in such openings respective bushings or sleeves 3I and 32 which are internally threaded to receive complementary threaded tubular connectors or caps 33 and 34. The caps 33 and 34 are formed with inclined shoulders at their upper ends to seat upon complementary shoulders formed in the shell openings I6 and I8. The caps 33 and 34 thus serve to align the manifold 28 with the shell flange I I and inhibit axial and rotative motion of the manifold and header plates 22 relatively to the shell I0.

It is observed that the connectors or caps 33 and 34 open into the manifold 28 so that the flange openings I2 and I3 are in communication with the interior of the manifold, and through the flow tubes 29 with the header chamber 26. The flange opening I4, however, does not communicate with the manifold 28. The opening 2|, which connects opening I4 to the interior of the shell I 0, overlies and extends beyond the diameter of manifold 23 for a free flow of the oil from or to the assembly of heat exchange tubes 24 in by-passing relation to the manifold 28.

The flange II has mounting bolts 35 set therein for the attachment of a suitable valve mechanism by which the flow of fluid through the heat exchange unit may be controlled. According to one known type of valve with which the heat exchange unit may be used, flange opening I2 serves as the inlet to the heat exchange unit, opening I3 serves as a by-pass outlet, and flange opening I4 serves as the principal outlet from the heat exchange unit. According to this operation of the device, the oil enters the unit by way of opening I2 and passes through chamber I5 and connector 33 to the interior of manifold 28. Within the manifold 28, the oil may flow through tubes 29 to header chamber 26, and from thence into the tortuous passage, defined by the bafiles 25, through the assembly of heat exchange tubes back to the top of the unit where it is discharged through shell opening 2I to outlet I4. In the conditioning of a congealable liquid, such as oil, cooling may be unnecessary in the early stage of the operation, and, further, a free flow of oil through the narrow spaces between the heat exchange tubes 24 may be inhibited on account of congealment. In this phase of the operation, therefore, the fluid entering the manifold 28 byway of inlet opening I2 may escape by way of by-pass opening I3 without passing through the flow tubes 29. As continued operation under conditions of pressure and increas ing heat make cooling necessary, and further result in decongealing or thinning of the oil between the heat exchange tubes, flow through the by-pass outlet I3 is discontinued and the fluid is compelled to follow the longer path represented by the flow tubes 29, header chamber 26, and the tortuous fluid flow passage defined by bafiles 25. Ordinarily, the valve to be mounted on flange I I incorporates automatic controls responding to the temperature or pressure or some other condition of the fluid to open and close the by-pass outlet I3. Additionally, selected ones or all of the flow tubes 29 may have small openings therein for the injection of heated fluid into the spaces between the heat exchange tubes 24 to assist in and speed up the process of decongealment.

The connections between the heat exchange tubes 24 and the header plates 22, and between the header plates and the shell I 0 may be accomplished by conventional brazing or soldering techniques establishing both a seal and a bond. Theinstant invention, however, has a special application and utility to a heat exchange unit shell.

t eir ust 21, 1948, for Construction for Heat Exchange- Devices. The present application may, inthis regard, be considered a continuation of that application. In that type of heat exchange unit, the projecting ends of the heat exchangetubes are surrounded. by a resilient ring seal which may seat in. a counterbore in the openings in the header plates, and which effectively inhibits the escape of fluid along the tubes outside the header plates. Further, in that type of device,.the periphery of the header plates is grooved to receive a ring seal which contacts'and seals the internal wall of the shell. A construction of the type described is illustrated in the present disclosure, the individual ring seals surrounding the ends of tubes 24 being indicated at 36, and the peripheral seal in the header plates bein indicated at 31..

According to one preferred method of assemblyof the heat exchange device of the invention, a pair of header plates 22, having the openings 23, recesses 21 and baflle grooves preformed therein are aligned and heat exchange tubes 24 are passed through the openings 23 therein, the entire core of heat exchange tubes being thus filled out except that part in which the manifold 28 is to be positioned. When these tubes 24 have been 50' inserted and their ends expanded and. ring seals 36 mounted thereon, the baflles 25' are inserted between the header plates. Following this,

not require or preclude utilization of the manifold space for cooling area, the heat exchange tubes contained therein may be omitted. In this case; as is the case in the vertical space occupied by the fiow tubes 29, the registering portions of thefheader plates are left blank, or, if already thesub-assembly, made up of the manifold 28 and flow. tubes 29, which has previously been brazed into an integral structure, is inserted, the manifold being received within the recesses 26 in the header plates and the flow tubes 29' passing through. registering openings in the bafiles 2,5 andextending downward into the header chamber. 26. Finally, additional heat exchange tubes24 are passed through the manifold 28 and. mounted in the header plates 22, it being noted here that the space in. the heat exchangev core occupied, by the manifold 28 is not lost as useful heat exchange area, but, rather, is filled or substantially filled with tubes 24 for cooling of the fluid passing through the manifold.

When the core unit, comprising header plates 22, heat exchange tubes 2 baffles 25, manifold 28, and flow tubes 29, has been so assembled, it is pushed into the supporting shell I0 and the ring seals 31, which have previously been mounted inthe peripheries of the header plates, make avsealingcontact with the internal wall of the The core unit is adjusted within the shell to align the bushings 3| and 32 on manifold; 28 with: the shell openings [6 and i8, whereupon the connector caps 33 and 34 are droppedinto place through the respective openings 12 and I3 and turned into, interconnecting relation with the manifold and shell. for the-mounting of a valve upon the flange ll and for use. i

While the manifold 28 is here shown as serving the primary purpose of facilitating installation of the flow tubes 29 and of permitting a fixed alignment of the core unit with the shell, the incorporating of such a manifold in'a core unit is thought to be broadly new. Other uses therefor will suggest themselves, as for example for the internal mounting of principal or auxiliary fluid flow control devices. If such other use does The device then is ready drilled with openings 23, are suitably plugged.

What is claimed is: 1. A heat exchange device, comprising a pair of spaced apart header plates each presenting a plurality of openings, an assembly of heat exchange. tubes supported between said plates insaid openings, a cylindrical shell in surrounding relation to said plates and said heat exchange ,-tubes,ffiuid sealing means between said tubes and said header plates and between said header "plates and 'said shell, a first opening in said. shell on one side of said tube assembly,a

second-opening ,in said shell circumferentially offset from said first opening, a tubular member supported between said header plates .in underlying relation to the said first opening .in said header plate and presenting an opening regise tering withsaid firstopening, the said second. opening, communicating with the tube assembly exteriorlyyof said tubular member, means defining with. said shell on the opposite side of said tube assembly a header chamber communicating withsaid tube assembly, and a row of spaced apart flow :tubes interconnecting said tubular member and said header chamber.

2.. A heat exchange device according to claim 1, characterized by a bushing extending through and between the said first opening in said shell and the opening in said tubular member serving to align said openings and fixing said member against movement relative to said shell.

3. A heat exchange device, comprising a core unit including an assembly of heat exchange tubesand a tubularmember arranged lengthw-ise ofsaid tube assembly within the circum of said assembly, a shell constituting a mounting for said core unit and surrounding said tube assembly andsaid tubular member, correspond ing openings in said shell and said tubular member adapted to register with one another, another opening in said shell communicating: with said tube assembly exteriorly of said tubular member, andspaced apart flow tubes com-- municating said tubular member with a portion of the tube assembly, remote fromv said other member;

4. A heat "exchange device,'compr'ising a core unit including an assembly of heat exchange tubes, means interconnecting'the ends of the tubes establishing a spaced relationship between.

the tubesdefining flow. passages therearound of.

a first .fluid, the tubes being open throughouttheir lengths for passage therethrough of. a sec ond .fiuid, means defining a longitudinal cham-' berin saidv tube assembly adjacent the periphery thereof onone side of the assembly, a shell providing a mounting for said core unit and surrounding" said tube assembly, a first opening throughsaidi shell into said longitudinal chamber, asecond opening through said shell into said tube assembly outside said longitudinal chamber, means defining with said shell a header chamber on the side of said tube assembly opposite said longitudinal chamber, and spaced apart flow tubes extending transversely through said tube assembly and interconnecting said longitudinal chamber and said header chamber.

5. A heat exchange device, comprising a core unit including an assembly of heat exchange tubes, means interconnecting the ends of the tubes establishing a spaced relationship between the tubes defining flow passages therearound of a first fluid, the tubes being open throughout their lengths for passage therethrough of a second fluid, means defining a longitudinal chamber in said tube assembly containing some of the tubes of said assembly and closed'from communication with the remainder of the assembly, said chamber being located adjacent the'periph ery of the tube assembly on one side thereof,"a shell providing a mounting for said core unit and surrounding said tube assembly, a first opening through said shell into said longitudinal chamber, a second opening through said shell opening into said tube assembly outside said longitudinal chamber, means defining with said shell an internal header chamber on the opposite side of said tube assembly, and spaced apart flow tubes extending transversely through said tube assembly and interconnecting said longitudinal chamber and said header chamber.

6. A heat exchange unit, comprising a core unit including a pair of spaced apart header plates presenting a plurality of openings, heat exchange tubes supported between said header plates in said openings for the flow of 'a first fluid around the tubes and for the fiow of a se'cond fluid through the tubes, means defining a longitudinal chamber within said tube assembly adjacent the periphery thereof on one side of the assembly; spaced apart flow tubes extending transversely from said chamber through the tube assembly to the opposite side thereof, and a shell providing a mounting for said core unit and surrounding said tube assembly, said shell pre senting a first opening communicating with said longitudinal chamber and a second opening communicating with said tube assembly outside said longitudinal chamber for the circulation of said first fluid through said core unit.

7. A heat exchange unit, comprising a shell, 3.

core unit to be mounted in said shell including an assembly of heat exchange tubes arranged in closely spaced relationship for the'pass'age of a first fluid around the tubes and'for the-passage of a second fluid through the tubes, means defining a longitudinal chamber within said tube assembly adjacent the periphery thereof, an opening from said chamber into the tube assembly, and a pair of openings in said shell, one opening into said longitudinal chamber and the other opening into the tube assembly outside said chamber, for the circulation of said first fluid through said core unit. Y

8. A heat exchange device according to claim '7, characterized in that said meansdefining a longitudinal chamber is a tubular member lying within the circumferential outline of said tube assembly and forming with said assembly an integral core unit received as a unit in the shell.

9. A heat exchange device according to claim 8, wherein said tubular member presents an opening to registerwith the first one of the said pair of openings in said shell, characterized by a bushing extending within and between said openings and inhibiting movement of said core unit relatively .to said shell.

10. A jacketless oil cooler, comprising a shell presenting first and second openings serving alternatively as the oil inlet and oil outlet, a core unit to be received in said shell and including an assembly of heat exchange tubes connected together at their ends and held in spaced relationship ior the passage of oil therearound, means defining a longitudinal chamber recessed into the periphery of said tube assembly, and spaced apart flow tubes extending from said longitudinal chamber transversely through the tube assembly to the peripheral area on the opposite side thereof, said first shell opening being located to communicate with said longitudinal chamber and said second shell opening being adjacent to the first but communicating with the tube assembly outside said longitudinal chamber.

11. A jacketless oil cooler, comprising spaced apart header plates presenting a large number of closely spaced openings therein, heat exchange tubes supported between said plates in said openings and spaced apart thereby for the flow of oil therearound between said plates, opposed recesses on the inner walls of said header plates contiguous with the peripheries of the plates, a tubular member having its ends seated in said recess, a series of spacedapart flow tubes extending transversely through the tube assembly and having their one ends received in said tubular member and having their other ends terminating in the peripheral area of said tube assembly on the side opposite said tubular member, a shell surrounding said header plates and said tube assembly, an oil flow opening through said shell into the interior of said tubular memher, and another oil flow opening through said shell into the tube assembly outside the tubular member.

12. A jacketless oil cooler according to claim 11 and of the class in which said header plates are sealed but not bonded with respect to said shell, characterized by a bushing extending through the first said'shell opening into said tubular member and inhibiting movement of the header plates and associated parts including said tubular member, said flow tubes and said heat exchange tubes relatively to the shell.

HARRY T. BOOTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

